Sends abstract of her BAAS paper on the role of a parasitic fungus in producing bisexual flowers in Lychnis.
28 Jackson's Row | Albert Square | Manchester
My dear M
Will you permit me to send you the enclosed abstract of a paper read at the Exeter Meeting of the British Association, respecting the curious variety of campion flowers I took the liberty of sending you a few years ago, and in which you were good enough to express some interest
If you think the subject worthy of your attention I should be greatly obliged if you would kindly inform me whether you think it possible that the fungus could exert what looks like an ``active coercive force to bend the structure of the flower to its necessities''. From all that I have observed I cannot rest in any other conclusion but in the enclosed abstract, I have merely given the result to which I have been led and not entered into the detailed reasons for it.
If you paid any attention to those plants which I sent you, you may have observed some facts which will bear on this curious question.
On your theory of Pangenesis it seems to me not inconceivable that gemmules of stamens may circulate undeveloped in the pistilliferous plants of campion, and that the presence of the parasite may cause the condition under which these can develop—but without this theory I am totally unable to conjecture in what manner the fungus possibly can cause stamens to grow in a flower that would not naturally have produced them.
Apologising for troubling you with this note I am |
yours very truly | Lydia E. Becker
Charles Darwin Esq—
<On alteration> in the structure of Lychnis diurna <observed in co>nnection with the development of a <parasitic> fungus
Abstract of Paper read before section D— British Association, Exeter—
Specimens were produced of the common red campion,
Lychnis diurna, infested with a parasitic fungus allied to
the ``smut'' in wheat which fungus develops its
fructification in the anthers of the flower. The campion in
its ordinary healthy state has flowers bearing stamens only
or pistils only, but about half the plants infested with
the parasitic fungus bear flowers containing both stamens
and pistils. The writer had never observed bisexual flowers
on healthy plants, and attributed the occurrence of that
condition in the specimens produced to the action of the
parasitic fungus. The diseased plants very rarely produce
seed but occasionally late in the season perfect capsules
bearing good seed are found on them. A few of the flowers
had been submitted to M
- f1 6937.f1The abstract appeared in Report of the thirty-ninth meeting of the British Association for the Advancement of Science, held at Exeter (Becker 1869a). CD and Becker had earlier corresponded on the possible dimorphism in Lychnis diurna (now Silene dioica, red campion) and CD had evidently alerted Becker to the fact that a fungus was the cause of the purple anthers she had observed (see Correspondence vol. 11, letter from L. E. Becker, 23--4 May  and n. 5).
- f2 6937.f2Becker refers to plants she sent with her letter of 21 May  (Correspondence vol. 11).
- f3 6937.f3Pangenesis, CD's hypothesis of the transmission and development of hereditary characters, is discussed in Variation 2: 357--404. CD suggested that each individual cell threw off minute particles (gemmules) that circulated in the bodily fluids and were capable of generating new cells, or remaining dormant until required. For more on the relation of the anther-smut fungus to male and female flowers of Silene dioica, see Giles et al. 2006.
- f4 6937.f4The enclosure is damaged. Missing parts have been restored from the published text (Becker 1869a).